Dental syringe



A. J. SON

DENTAL SYRINGE Oct. 11, 1949.

2 Sheeis-She'et 1 Filed July 14, 1948 INVENTOR.

Oct. 11, 1949. A. J. SON 2,484,657

DENTAL SYRINGE Filed July 14, 1948 '2 Sheets-Sheet 2 IN VENTOR Patented Oct. 11, 1949 DENTAL SYRINGE Anthony J. Son, Mattapan, Mass, assignor to Sonco, Inc, Mattapan, Mass., a corporat on of Massachusetts Application July 14, 1948, Serial No. 38,654

Claims.

The present invention relates to subcutaneous injection instruments, and more especially to those of the type commonly known as dental syringes.

The general object of the invention is to improve and simplify the construction of such instruments and reduce the cost thereof, and to increase the useful life and efficiency of the needle.

A special .object :of the invention is to provide a very simple quick-acting locking means for removably securing the needle to the syringe body and for easily removing the same.

Another object is to provide a new and improved hub for the needle, so shaped that, by co-operation with an adapter, it insures the firm locking together of the needle and syringe body manually and without the use of implements.

A further object, is the provision of an adapter capable of use with the standard type of injection instruments whereby the locking aforesaid is effected and the needle may be removed without removing the adapter.

Still another object of the invention is the provision of means, herein shown as a sleeve, enclosing any desired length of the needle for stifiening said needle and preventing the breaking or bending of the latter, thereby greatly in.- creasing the useful life of the needle.

A still further object is the provision of a needle support member adjustablelon itudinally in said adapter in combination with means securing the needle in adjusted position in order to govern the depth of penetrhtiOn of the needle.

With these, and other objects in View, ,my invention consists ofthenovel features, parts, and combination of parts, which are particularly described in connection with the accompanying drawings illustrating a dental y iinge that has given good results in practice.

In the drawings which accompany and form a part of this specification,

Figure 1 is a front elevation of a dental syringe embodying my invention.

Fig. 2 is a side elevation of said syringe, :taken at right angles :to the view in Fig. 1.

Fig. 3 isa longitudinalsectiontaken on the line 3-3 of Fig. ;1.

Fig. 4 is a front elevation of a dental syringe needle and its hub embodying my invention.

Fig. 5 is a side elevation thereof.

Fig. 6 is a plan elevation of said needle andhub.

Figs. 7 and-8 are elevations of stifiening sleeves for the needle.

Fig. 9 is an elevation of the needle to which a stiffening sleeve has been applied.

Fig. 10 is a fragmentary section, partly in elevation, ,of the inner end of the syringe body with the needle in place, the locking means being omitted.

Fig. 11 is an elevation of the inner end of the syringe body, the needle the locking means.

Fig. 12 is a horizontal section taken on the line I2l2 of Fig. 1 1.

Fig. 13 is a horizontal section taken on the line I l-I l showing the position of the hub after it has been inserted in the adapter but before the latter has been rotated clockwise with respectto the syringe body or the latter rotated counterclockwise with respect to the adapter.

Fig. 14 is a section taken on the line r-44 showing the positionof the hub after the needle has been locked to the syringe body.

In the particular drawings selected for more fully disclosing ,my invention and the principles underlying the same, said drawings to .be considered as illustrative, merely, and by no means, restrictive z fl is a dental syringe bodyof the usual type having a plunger 21 and a spring finger 22 for securing the ampule (not shown) in position after it has been inserted inthesyringe body.

It will be understood, of course, that the outer end of the needle Zipenetrates the closure of the ampule, and that the plunger is inserted in the other end of the ampule and ,co-operates with a disc therein for forcing the contents of the amu h ugh he nee l e ing elfti u arly :Fis 111-1 inclusive. which illustrate .oneform of locking means which in practice has been found very efiective, the means gfOI lockingthe needle to the syringe comprises ,what lhterjm anadapterdfi which, as shown in Figs. 1,2, and performs in connection with another member, the fu1'iction of governing the depth of penetration of the needle.

In the present instance, the locking means or adapter comprises a block having a central longitudinalcayity; 2,5 open at the top and terminating in a threaded hole ,26 for receiving a hollow threaded studez'l, which projects from the inner end of the syringe body. The adapter has also a transverse cavity 28 which extends through the walls thereof and of course intersects said longitudinal cavity. The cavity formed by the intersection of these two cavities is shaped to permit of limited rotational v.rnove 'nent of "the needle hub 29 of at leasteil-degreesand for movement of said hub in the direction of the axis of will be moved axially against the undersurfaces 33 of the top of the transverse cavity under which the ends of the hub have been turned by the rotation aforesaid. v V V f After the hub has been inserted through the longitudinal cavity 25, the operator grasps the adapter with one hand, and with the other, ro-

Having thus described an illustrative embodiment of my invention without, however, limiting the same thereto, various modifications within the purview of the appended claims being permissible, what I claim and desire to secure by Letters Patent is:

1. A dental syringe comprising in combination, a syringe body, an injection needle, a hub secured to said needle intermediate the ends thereof and a locking member interposed between said needle and said syringe body, said locking memher having a cavity in which said hub is disposed for limited rotational movement and for movement in the direction of the axis of said syringe body, andscrew means formed on the inner end of said syringe body and in threaded engagement with said locking member, whereby upon 7 relative rotary movement of said locking member tates the syringe body about one-half turn counterclockwise, or else rotates the adapter while holding the syringe body stationary, whereupon the friction between the hub and the threaded stud 21 will cause the rotation of the hub from the position shown in Fig. 13 to that shown in Fig. 14, and, at the same time, the hub and the needle to which it is secured will be moved axially against the surfaces 33 aforesaid, which form an abutment for the hub and thus prevent further rotational movement thereof.

It is to be understood, however, that various other means may be employed for locking together the needle hub and the syringe body.

The needle hub comprises the sleeve portion 34, the cross piece 29, herein shown as a rectangular paral'lelopiped, and the inverted frustoconical portion 35, said sleeve and frustoconical portion extending oppositely from the inner and outer faces of the hub, respectively. The stud on the upper end of the syringe body is hollow for receiving the outer end of the needle 23 and terminates at its inner end in a conical cavityfor receiving the inverted frustoconical portion of the hub which fits tightly therein.

It is a well known fact that dentalv needles,

which are usually made of an alloy of chromium and nickel, are frequently bent out of shape and that after they have been straightened, the bore thereof is constricted at the point of the bend. In order to stiffen the needle to prevent bending or breaking, I provide sleeves 36, 3B, of different lengths, secured to the inner end of each of which is a button 31 which limits the depth of penetration of the needle in the patients jaw or other member to be treated. The sleeves which tightly embrace the needle with which they are used are of difierent lengths, rthus enabling the dentist to limit the maximum depth of penetration of the needle, each sleeve being, of course, of less length than the needle itself. The outer ends of the sleeves preferably are disposed, respectively, between the needle and the hub sleeve 34, as shown at 34. A more convenient way, however, of governing such depth of penetration is afforded by the use of a rod member 38, a-djustably secured to the adapter 24 and lockable in adjusted position by the set screw 39, said member having a sleeve 39 fixedly :at-

tached to its upper end by a collar 40, or other suitable means, said collar serving to hold said sleeve fixedly, and in alignment with the axis of the needle. By loosening the set screw 39, the rod and the collar held thereby may be adjusted axially of the needle and locked in adjusted position to fix the depth to which the needle may be inserted in the patients gum.

and syringe body, said hub will be rotated against the side of said locking means and moved axially against an abutment formed therein.

2. A dental syringe comprising in combination, a syringe body having a hollow threaded stud projecting from the inner end thereof, an injection needle having a hub intermediate the ends thereof and normal to the axis of said needle, an adapter having a central longitudinal cavity shaped to receive the hub of said needle and terminating in a threaded hole for receiving said stud, said adapter having a transverse cavity in tersecting said longitudinal cavity, the cavity formed by the intersection of said longitudinal and transverse cavities being shaped to permit the rotation of said hub therein through an arc of at least whereby when the hub of said needle is inserted in said longitudinal cavity and the stud on the inner end of said syringe body is inserted in the threaded hole in said adapter and the syringe body rotated with respect to said adapter, said hub will be rotated through an arc of approximately 90 and forced against the inner walls of said cavity, thereby locking securely together said syringe body, adapter, hub, and the needle carried by the latter.

3. In a dental syringe, means for stiffening the syringe needle and adjusting the depth of penetration thereof, said means comprising a bracket member detachably secured to the syringe body at the inner end thereof, a rod member adjustably secured to said bracket member, means for locking said rod member in adjusted position, and a sleeve member fixedly attached to said rod member, said sleeve member being disposed to embrace the syringe needle and being of less length than the latter.

4. In a dental syringe, an injection needle, a hub secured thereto intermediate the ends there of, said hub comprising a sleeve portion extending from the inner face of said hub, a sleeve embracing said needle and terminating short of the pointed end thereof, the inner end of said sleeve being provided with a button and the outer end thereof being disposed within the sleeve portion of the hub. I

5. A dental syringe comprising in combination, a syringe body, a threaded stud formed on the inner end of said body, an injection needle, a cross member secured to said needle intermediate the ends thereof and angularly related thereto, and a locking member adapted to receive said cross member, said locking member being interposed between said cross member and said syringe body and being provided with a threaded hole on its outer face for receiving said threaded stud, whereby upon relative rotary movement of the 5 locking member and syringe body, said cross Number member and the needle carried. thereby will be 1,274,081 locked to the syringe body. 1,523,068 ANTHONY J. SON. 1,526,824 5 1,668,315 REFERENCES CITED 107 121 The following references are of record in the file of this patent:

Number UNITED STATES PATENTS 10 13 142 Number Name Date 766,203 Walsh Aug. 2, 1904 Name Date Riethmueller July 30, 1918 Hein Jan. 13, 1925 Bock Feb. 17, 1925 Hein May 1, 1928 Dickinson Apr. 6, 1937 FOREIGN PATENTS Country Date Great Britain May 28, 1914 

